feat(server): INGEST_WING_ROUTING wires the Router; remove the classifier path (#208)

Removes the LLM classifier, the substring 'BM25' scorer, the agreement gate,
the backtest and the old migrate/wingmigrate tooling: measured at 2 of 55
pages placed (#208), and the migration was built for the per-wing facts layout
this branch replaces. wing now holds the decision types, the Router and
KnownWings. INGEST_WING_ROUTING=1 builds the Router (default wing
INGEST_DEFAULT_WING=web-clip, client pattern from INGEST_CLIENT_BLOCK or
CLAUDE_INGEST_CLIENT_BLOCK); a bad default or pattern is fatal at startup.
Watcher tests rewritten for the Router, including a deliberate subfolder into
any existing wing, typo'd folders parked, forged-key and edit-while-placing
cases.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

ingestion/internal/wing/router.go

@@ -8,12 +8,6 @@ import (
 	"strings"
 )
 
-// Placer decides where a raw note goes. Router is the production
-// implementation; the interface lets the watcher stay ignorant of how.
-type Placer interface {
-	Resolve(ctx context.Context, n Note) Decision
-}
-
 // Router places a note with rules only, no model (hyperguild#208):
 //
 //  1. A subfolder or frontmatter `wing:` is the owner's deliberate choice. It
@@ -68,3 +62,23 @@ func (r Router) explicit(w, via string) Decision {
 	}
 	return Decision{Wing: w, Source: Explicit, Confidence: 1, Reason: "named by " + via}
 }
+
+// NewRouter builds the production Router. defaultWing must be a plain wing
+// name; clientPattern, when set, is a case-insensitive regexp over note text
+// whose match parks an unsignalled note instead of filing it. Both fail at
+// startup rather than later: a client filter that silently does nothing is
+// worse than none.
+func NewRouter(brainDir, defaultWing, clientPattern string) (Router, error) {
+	if defaultWing == "" || !plainWingName(defaultWing) {
+		return Router{}, fmt.Errorf("default wing %q is not a plain wing name", defaultWing)
+	}
+	r := Router{BrainDir: brainDir, Default: defaultWing}
+	if clientPattern != "" {
+		re, err := regexp.Compile("(?i)" + clientPattern)
+		if err != nil {
+			return Router{}, fmt.Errorf("client-content pattern: %w", err)
+		}
+		r.ClientBlock = re
+	}
+	return r, nil
+}